<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- CSS -->
    <link href="/css/bootstrap.min.css" rel="stylesheet">
    <!-- jQuery and JavaScript Bundle with Popper -->
    <script src="/js/jquery.slim.min.js"></script>
    <script src="/js/bootstrap.bundle.min.js"></script>
    <title>
    <?php
    if (!isset($title)) {
        $title = '欢迎使用';
    }
    echo $title;
    ?>
    </title>
</head>
